/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2016 Joyent, Inc.
 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
 * Copyright 2022 Garrett D'Amore
 */
/* Copyright (c) 1990 Mentat Inc. */

#include <inet/ip.h>
#include <inet/tcp_impl.h>
#include <inet/cc.h>
#include <sys/sunddi.h>

/* Max size IP datagram is 64k - 1 */
#define TCP_MSS_MAX_IPV4 (IP_MAXPACKET - (sizeof (ipha_t) + sizeof (tcpha_t)))
#define TCP_MSS_MAX_IPV6 (IP_MAXPACKET - (sizeof (ip6_t) + sizeof (tcpha_t)))

/* Max of the above */
#define TCP_MSS_MAX             TCP_MSS_MAX_IPV4

typedef struct {
        char *ccn_buf;
        uint_t ccn_bufsize;
        uint_t ccn_bytes;
} tcp_copy_ccname_t;

/*
 * Set the RFC 1948 pass phrase
 */
/* ARGSUSED */
static int
tcp_set_1948phrase(netstack_t *stack,  cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void* pr_val, uint_t flags)
{
        if (flags & MOD_PROP_DEFAULT)
                return (ENOTSUP);

        /*
         * Basically, value contains a new pass phrase.  Pass it along!
         */
        tcp_iss_key_init((uint8_t *)pr_val, strlen(pr_val),
            stack->netstack_tcp);
        return (0);
}

/*
 * returns the current list of listener limit configuration.
 */
/* ARGSUSED */
static int
tcp_listener_conf_get(netstack_t *stack, mod_prop_info_t *pinfo,
    const char *ifname, void *val, uint_t psize, uint_t flags)
{
        tcp_stack_t     *tcps = stack->netstack_tcp;
        tcp_listener_t  *tl;
        char            *pval = val;
        size_t          nbytes = 0, tbytes = 0;
        uint_t          size;
        int             err = 0;

        bzero(pval, psize);
        size = psize;

        if (flags & (MOD_PROP_DEFAULT|MOD_PROP_PERM|MOD_PROP_POSSIBLE))
                return (0);

        mutex_enter(&tcps->tcps_listener_conf_lock);
        for (tl = list_head(&tcps->tcps_listener_conf); tl != NULL;
            tl = list_next(&tcps->tcps_listener_conf, tl)) {
                if (psize == size)
                        nbytes = snprintf(pval, size, "%d:%d",  tl->tl_port,
                            tl->tl_ratio);
                else
                        nbytes = snprintf(pval, size, ",%d:%d",  tl->tl_port,
                            tl->tl_ratio);
                size -= nbytes;
                pval += nbytes;
                tbytes += nbytes;
                if (tbytes >= psize) {
                        /* Buffer overflow, stop copying information */
                        err = ENOBUFS;
                        break;
                }
        }

        mutex_exit(&tcps->tcps_listener_conf_lock);
        return (err);
}

/*
 * add a new listener limit configuration.
 */
/* ARGSUSED */
static int
tcp_listener_conf_add(netstack_t *stack, cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void* pval, uint_t flags)
{
        tcp_listener_t  *new_tl;
        tcp_listener_t  *tl;
        long            lport;
        long            ratio;
        char            *colon;
        tcp_stack_t     *tcps = stack->netstack_tcp;

        if (flags & MOD_PROP_DEFAULT)
                return (ENOTSUP);

        if (ddi_strtol(pval, &colon, 10, &lport) != 0 || lport <= 0 ||
            lport > USHRT_MAX || *colon != ':') {
                return (EINVAL);
        }
        if (ddi_strtol(colon + 1, NULL, 10, &ratio) != 0 || ratio <= 0)
                return (EINVAL);

        mutex_enter(&tcps->tcps_listener_conf_lock);
        for (tl = list_head(&tcps->tcps_listener_conf); tl != NULL;
            tl = list_next(&tcps->tcps_listener_conf, tl)) {
                /* There is an existing entry, so update its ratio value. */
                if (tl->tl_port == lport) {
                        tl->tl_ratio = ratio;
                        mutex_exit(&tcps->tcps_listener_conf_lock);
                        return (0);
                }
        }

        if ((new_tl = kmem_alloc(sizeof (tcp_listener_t), KM_NOSLEEP)) ==
            NULL) {
                mutex_exit(&tcps->tcps_listener_conf_lock);
                return (ENOMEM);
        }

        new_tl->tl_port = lport;
        new_tl->tl_ratio = ratio;
        list_insert_tail(&tcps->tcps_listener_conf, new_tl);
        mutex_exit(&tcps->tcps_listener_conf_lock);
        return (0);
}

/*
 * remove a listener limit configuration.
 */
/* ARGSUSED */
static int
tcp_listener_conf_del(netstack_t *stack, cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void* pval, uint_t flags)
{
        tcp_listener_t  *tl;
        long            lport;
        tcp_stack_t     *tcps = stack->netstack_tcp;

        if (flags & MOD_PROP_DEFAULT)
                return (ENOTSUP);

        if (ddi_strtol(pval, NULL, 10, &lport) != 0 || lport <= 0 ||
            lport > USHRT_MAX) {
                return (EINVAL);
        }
        mutex_enter(&tcps->tcps_listener_conf_lock);
        for (tl = list_head(&tcps->tcps_listener_conf); tl != NULL;
            tl = list_next(&tcps->tcps_listener_conf, tl)) {
                if (tl->tl_port == lport) {
                        list_remove(&tcps->tcps_listener_conf, tl);
                        mutex_exit(&tcps->tcps_listener_conf_lock);
                        kmem_free(tl, sizeof (tcp_listener_t));
                        return (0);
                }
        }
        mutex_exit(&tcps->tcps_listener_conf_lock);
        return (ESRCH);
}

static int
tcp_set_buf_prop(netstack_t *stack, cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void *pval, uint_t flags)
{
        return (mod_set_buf_prop(stack->netstack_tcp->tcps_propinfo_tbl, stack,
            cr, pinfo, ifname, pval, flags));
}

static int
tcp_get_buf_prop(netstack_t *stack, mod_prop_info_t *pinfo, const char *ifname,
    void *val, uint_t psize, uint_t flags)
{
        return (mod_get_buf_prop(stack->netstack_tcp->tcps_propinfo_tbl, stack,
            pinfo, ifname, val, psize, flags));
}

/*
 * Special checkers for smallest/largest anonymous port so they don't
 * ever happen to be (largest < smallest).
 */
/* ARGSUSED */
static int
tcp_smallest_anon_set(netstack_t *stack, cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void *pval, uint_t flags)
{
        unsigned long new_value;
        tcp_stack_t *tcps = stack->netstack_tcp;
        int err;

        if ((err = mod_uint32_value(pval, pinfo, flags, &new_value)) != 0)
                return (err);
        /* mod_uint32_value() + pinfo guarantees we're in TCP port range. */
        if ((uint32_t)new_value > tcps->tcps_largest_anon_port)
                return (ERANGE);
        pinfo->prop_cur_uval = (uint32_t)new_value;
        return (0);
}

/* ARGSUSED */
static int
tcp_largest_anon_set(netstack_t *stack, cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void *pval, uint_t flags)
{
        unsigned long new_value;
        tcp_stack_t *tcps = stack->netstack_tcp;
        int err;

        if ((err = mod_uint32_value(pval, pinfo, flags, &new_value)) != 0)
                return (err);
        /* mod_uint32_value() + pinfo guarantees we're in TCP port range. */
        if ((uint32_t)new_value < tcps->tcps_smallest_anon_port)
                return (ERANGE);
        pinfo->prop_cur_uval = (uint32_t)new_value;
        return (0);
}

/* ARGSUSED */
static int
tcp_set_cc_algorithm(netstack_t *stack, cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void *pval, uint_t flags)
{
        tcp_stack_t *tcps = stack->netstack_tcp;
        char *name = (flags & MOD_PROP_DEFAULT) ?
            CC_DEFAULT_ALGO_NAME : (char *)pval;
        struct cc_algo *algo = cc_load_algo(name);

        if (algo == NULL) {
                return (EINVAL);
        }

        tcps->tcps_default_cc_algo = algo;

        return (0);
}

static int
tcp_copy_ccname(void *data, struct cc_algo *algo)
{
        tcp_copy_ccname_t *cd = data;
        char *sep = cd->ccn_bytes > 0 ? "," : "";
        size_t avail = 0;

        if (cd->ccn_bytes < cd->ccn_bufsize) {
                avail = cd->ccn_bufsize - cd->ccn_bytes;
        }

        cd->ccn_bytes += snprintf(cd->ccn_buf + cd->ccn_bytes, avail,
            "%s%s", sep, algo->name);

        return (cd->ccn_bytes >= cd->ccn_bufsize ? ENOBUFS : 0);
}

/* ARGSUSED */
static int
tcp_get_cc_algorithm(netstack_t *stack, mod_prop_info_t *pinfo,
    const char *ifname, void *pval, uint_t psize, uint_t flags)
{
        size_t nbytes;

        if (flags & MOD_PROP_POSSIBLE) {
                tcp_copy_ccname_t cd = { pval, psize, 0 };
                return (cc_walk_algos(tcp_copy_ccname, &cd));
        } else if (flags & MOD_PROP_PERM) {
                nbytes = snprintf(pval, psize, "%u", MOD_PROP_PERM_RW);
        } else if (flags & MOD_PROP_DEFAULT) {
                nbytes = snprintf(pval, psize, "%s", CC_DEFAULT_ALGO_NAME);
        } else {
                nbytes = snprintf(pval, psize, "%s",
                    stack->netstack_tcp->tcps_default_cc_algo->name);
        }
        if (nbytes >= psize)
                return (ENOBUFS);
        return (0);
}

/*
 * All of these are alterable, within the min/max values given, at run time.
 *
 * Note: All those tunables which do not start with "_" are Committed and
 * therefore are public. See PSARC 2010/080.
 */
mod_prop_info_t tcp_propinfo_tbl[] = {
        /* tunable - 0 */
        { "_time_wait_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*SECONDS, TCP_TIME_WAIT_MAX, 1*MINUTES}, {1*MINUTES} },

        { "_conn_req_max_q", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, UINT32_MAX, 128}, {128} },

        { "_conn_req_max_q0", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, UINT32_MAX, 1024}, {1024} },

        { "_conn_req_min", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, 1024, 1}, {1} },

        { "_conn_grace_period", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0*MS, 20*SECONDS, 0*MS}, {0*MS} },

        { "_cwnd_max", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {128, ULP_MAX_BUF, 1024*1024}, {1024*1024} },

        { "_debug", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 10, 0}, {0} },

        { "smallest_nonpriv_port", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1024, (32*1024), 1024}, {1024} },

        { "_ip_abort_cinterval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*SECONDS, UINT32_MAX, 3*MINUTES}, {3*MINUTES} },

        { "_ip_abort_linterval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*SECONDS, UINT32_MAX, 3*MINUTES}, {3*MINUTES} },

        /* tunable - 10 */
        { "_ip_abort_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {500*MS, UINT32_MAX, 5*MINUTES}, {5*MINUTES} },

        { "_ip_notify_cinterval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*SECONDS, UINT32_MAX, 10*SECONDS},
            {10*SECONDS} },

        { "_ip_notify_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {500*MS, UINT32_MAX, 10*SECONDS}, {10*SECONDS} },

        { "_ipv4_ttl", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, 255, 64}, {64} },

        { "_keepalive_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*SECONDS, 10*DAYS, 2*HOURS}, {2*HOURS} },

        { "_maxpsz_multiplier", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 100, 10}, {10} },

        { "_mss_def_ipv4", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, TCP_MSS_MAX_IPV4, 536}, {536} },

        { "_mss_max_ipv4", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, TCP_MSS_MAX_IPV4, TCP_MSS_MAX_IPV4},
            {TCP_MSS_MAX_IPV4} },

        { "_mss_min", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, TCP_MSS_MAX, 108}, {108} },

        { "_naglim_def", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, (64*1024)-1, (4*1024)-1}, {(4*1024)-1} },

        /* tunable - 20 */
        { "_rexmit_interval_initial", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*MS, 20*SECONDS, 1*SECONDS}, {1*SECONDS} },

        { "_rexmit_interval_max", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*MS, 2*HOURS, 60*SECONDS}, {60*SECONDS} },

        { "_rexmit_interval_min", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*MS, 2*HOURS, 400*MS}, {400*MS} },

        { "_deferred_ack_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*MS, 1*MINUTES, 100*MS}, {100*MS} },

        { "_snd_lowat_fraction", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 16, 10}, {10} },

        { "_dupack_fast_retransmit", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, 10000, 3}, {3} },

        { "_ignore_path_mtu", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_FALSE}, {B_FALSE} },

        { "smallest_anon_port", MOD_PROTO_TCP,
            tcp_smallest_anon_set, mod_get_uint32,
            {1024, ULP_MAX_PORT, 32*1024}, {32*1024} },

        { "largest_anon_port", MOD_PROTO_TCP,
            tcp_largest_anon_set, mod_get_uint32,
            {1024, ULP_MAX_PORT, ULP_MAX_PORT},
            {ULP_MAX_PORT} },

        { "send_buf", MOD_PROTO_TCP,
            tcp_set_buf_prop, tcp_get_buf_prop,
            {TCP_XMIT_LOWATER, ULP_MAX_BUF, TCP_XMIT_HIWATER},
            {TCP_XMIT_HIWATER} },

        /* tunable - 30 */
        { "_xmit_lowat", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {TCP_XMIT_LOWATER, ULP_MAX_BUF, TCP_XMIT_LOWATER},
            {TCP_XMIT_LOWATER} },

        { "recv_buf", MOD_PROTO_TCP,
            tcp_set_buf_prop, tcp_get_buf_prop,
            {TCP_RECV_LOWATER, ULP_MAX_BUF, TCP_RECV_HIWATER},
            {TCP_RECV_HIWATER} },

        { "_recv_hiwat_minmss", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, 65536, 4}, {4} },

        { "_fin_wait_2_flush_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1*SECONDS, 2*HOURS, 60*SECONDS},
            {60*SECONDS} },

        { "max_buf", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {8192, ULP_MAX_BUF, 1024*1024}, {1024*1024} },

        { "_strong_iss", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 2, 2}, {2} },

        { "_rtt_updates", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 65536, 20}, {20} },

        { "_wscale_always", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_TRUE}, {B_TRUE} },

        { "_tstamp_always", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_FALSE}, {B_FALSE} },

        { "_tstamp_if_wscale", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_TRUE}, {B_TRUE} },

        /* tunable - 40 */
        { "_rexmit_interval_extra", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0*MS, 2*HOURS, 0*MS}, {0*MS} },

        { "_deferred_acks_max", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 16, 2}, {2} },

        { "_slow_start_after_idle", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 16384, 0}, {0} },

        { "_slow_start_initial", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 16, 0}, {0} },

        { "sack", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 2, 2}, {2} },

        { "_ipv6_hoplimit", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, IPV6_MAX_HOPS, IPV6_DEFAULT_HOPS},
            {IPV6_DEFAULT_HOPS} },

        { "_mss_def_ipv6", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, TCP_MSS_MAX_IPV6, 1220}, {1220} },

        { "_mss_max_ipv6", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, TCP_MSS_MAX_IPV6, TCP_MSS_MAX_IPV6},
            {TCP_MSS_MAX_IPV6} },

        { "_rev_src_routes", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_FALSE}, {B_FALSE} },

        { "_local_dack_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {10*MS, 500*MS, 50*MS}, {50*MS} },

        /* tunable - 50 */
        { "_local_dacks_max", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 16, 8}, {8} },

        { "ecn", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 2, 1}, {1} },

        { "_rst_sent_rate_enabled", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_TRUE}, {B_TRUE} },

        { "_rst_sent_rate", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, UINT32_MAX, 40}, {40} },

        { "_push_timer_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, 100*MS, 50*MS}, {50*MS} },

        { "_use_smss_as_mss_opt", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_FALSE}, {B_FALSE} },

        { "_keepalive_abort_interval", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, UINT32_MAX, 8*MINUTES}, {8*MINUTES} },

        /*
         * tcp_wroff_xtra is the extra space in front of TCP/IP header for link
         * layer header.  It has to be a multiple of 8.
         */
        { "_wroff_xtra", MOD_PROTO_TCP,
            mod_set_aligned, mod_get_uint32,
            {0, 256, 32}, {32} },

        { "_dev_flow_ctl", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean,
            {B_FALSE}, {B_FALSE} },

        { "_reass_timeout", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {0, UINT32_MAX, 100*SECONDS}, {100*SECONDS} },

        /* tunable - 60 */
        { "extra_priv_ports", MOD_PROTO_TCP,
            mod_set_extra_privports, mod_get_extra_privports,
            {1, ULP_MAX_PORT, 0}, {0} },

        { "_1948_phrase", MOD_PROTO_TCP,
            tcp_set_1948phrase, NULL, {0}, {0} },

        { "_listener_limit_conf", MOD_PROTO_TCP,
            NULL, tcp_listener_conf_get, {0}, {0} },

        { "_listener_limit_conf_add", MOD_PROTO_TCP,
            tcp_listener_conf_add, NULL, {0}, {0} },

        { "_listener_limit_conf_del", MOD_PROTO_TCP,
            tcp_listener_conf_del, NULL, {0}, {0} },

        { "_iss_incr", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32,
            {1, ISS_INCR, ISS_INCR},
            {ISS_INCR} },

        { "congestion_control", MOD_PROTO_TCP,
            tcp_set_cc_algorithm, tcp_get_cc_algorithm, {0}, {0} },

        /* RFC 3465 - TCP Congestion Control with Appropriate Byte Counting */
        { "_abc", MOD_PROTO_TCP,
            mod_set_boolean, mod_get_boolean, {B_TRUE}, {B_TRUE} },

        /* "L" value from RFC 3465 */
        { "_abc_l_var", MOD_PROTO_TCP,
            mod_set_uint32, mod_get_uint32, {1, UINT32_MAX, 2}, {2} },

        { "?", MOD_PROTO_TCP, NULL, mod_get_allprop, {0}, {0} },

        { NULL, 0, NULL, NULL, {0}, {0} }
};

int tcp_propinfo_count = A_CNT(tcp_propinfo_tbl);